View clinical trials related to Caffeine.
Filter by:The main objective of the study is to evaluate the influence of caffeine intake on participants' energetic arousal, affect, motivation to achieve a training goal, satisfaction with training, and the sense of agency during training. Consequently, participants will engage in three sessions: caffeine, placebo, and no substance (in counterbalanced order). During each session, their affective and motivational states will be assessed, along with the performance of a standardized physical exercise test. The investigators hypothesize that participants who consume caffeine (caffeine condition) will exhibit higher levels of energy and motivation compared to the other two groups. Additionally, they are expected to experience greater optimism and expectancy regarding their training goals and achieve better results in the physical exercise test. A secondary aim of the study is to examine the impact of genetic variability on motivational and affective states of participants, as well as their performance in the physical exercise test after caffeine. The investigators will assess the CYP1A2 (-163C > A, rs762551; characterized such as "fast" (AA genotype) and "slow" caffeine metabolizers (C-carriers)) and ADORA2A (1976T > C; rs5751876; characterized by "high" (TT genotype) or "low" sensitivity to caffeine (C-carriers)).
The goal of this clinical trial is to systematically investigate two prominent factors in teenagers' daily life: Caffeine and sleep restriction (SR) and their combined influence on sleep, cognition, and behavior in healthy adolescents. The main questions it aims to answer are: The effects of caffeine under conditions of SR and SE: - on sleep pressure and sleep continuity. - on BOLD activity differences in reward related areas during a reward task (monetary incentive delay task) and on reaction times (behavioral aspect) in the same task. - on BOLD activity differences during a risk taking task (wheel of fortune task) and on risky decision-making (behavioral aspect) in the same task. Participants will be either in the SR or SE condition (between-subject). The protocol consists of 2x of approximately one week in which a participant will receive caffeine or placebo (within-subject) at the last two evenings. The experiment consists of an ambulatory and a laboratory phase: - The ambulatory phase consists of 5 nights, including 3 stabilization nights (8h sleep opportunity) prior to 2 nights consisting of either SR with 6h sleep opportunity or SE with 9.5h sleep opportunity. Participants will wear an actiwatch and fill out sleep diaries during this period. - The laboratory phase will be the 6th evening, night and morning of the protocol and will be spent in our lab. Participants will do the following: - treatment (caffeine vs. placebo) intake - saliva sampling - drug screening - cognitive tests, including risk-taking and reward task - filling in questionnaires (sleep diary, sleep quality, sleepiness, mood, expectancy) - waking and sleep with EEG The next day, participants will undergo an fMRI scan, including the following: - resting-state scan - structural scan - arterial spin labeling scan - reward task scan - risk-taking task scan Around the scan, participants will fill out/undergo: - saliva sampling - questionnaires (reward task, mood, sleepiness, expectancy)
Several high-altitude destinations recommend their visitors to avoid caffeine, theoretically due to the associated diuresis which could contribute to acute mountain sickness. There is however no direct evidence for this association. In fact, caffeine ingestion is known to improve exercise performance at sea level, and may therefore help mountaineers during expeditions. Sport science research is largely conducted in male participants, and the findings from these studies are assumed to apply to the female population. Given the known sex differences in body composition, hormones, and other physiological factors, this may not be appropriate. It is therefore important to conduct research in women, to allow for female-specific recommendations.
The purpose of this study is to learn about the change in quality of sleep, structural organization of sleep, and cardiovascular responses after consuming an energy drink compared to a placebo drink with no caffeine or stimulants.
Introduction: The caffeine is used in the treatment for apnea of prematurity and it has several positive effects in the neurodevelopment of preterm babies. There are innumerable observational studies suggesting that initiating caffeine in the first hours of life may offer more benefits in the reduction of the necessity of intubation and in ventilation time. It is necessary to expand further research on the best time to start caffeine, which may improve the quality of care for premature infants. Objective: To evaluate the benefits of caffeine administration in the first two hours of life compared to administration at 24 hours of life in premature patients on noninvasive mechanical ventilation with birth weights less than 1250 grams. Methodology: Preterm newborn patients with birth weight < 1250 grams born at Hospital de Clínicas de Porto Alegre who are not intubated in the delivery room will be included. Patients will be randomized into two groups. One arm of the study will receive caffeine at 2 hours of age and the other arm will receive caffeine at 24 hours of age (control). Patients in the control group will receive 0.9% SF at 2 hours of life in order to keep the study blinded. The following outcomes will be evaluated: need for intubation, time on invasive and non-invasive mechanical ventilation, BPD, necrotizing enterocolitis, need for ROP treatment, PDA with hemodynamic repercussions, peri-intraventricular hemorrhage, leukomalacia and death. The sample size calculation is 50 patients, 25 in each arm. Expected Results: It is expected to find a 43% reduction in the need for intubation in preterm infants who receive caffeine in the first two hours of life compared to administration at 24 hours of life. It is also expected to find a reduction in mechanical ventilation time, in addition to a possible reduction in negative outcomes associated with prematurity.
"Learning from the rewards" is underlying the formulation of knowledge and habits in daily life. Caffeine is the most commonly used "psychoactive" substance that could change one's mind state by affecting the brain and nervous system. By such effects, caffeine enhances reward signals - dopamine - in human brains. In this research study, we will find out whether taking caffeine acutely or daily can enhance reward learning processes.
Several studies have shown the positive effect that caffeine has on athletic performance related variables. Nonetheless, most studies have been developed in males and have not studied the possible effects on biomechanics and related injuries. Moreover, the inclusion of personalized insoles could also affect biomechanical patterns and thus injury incidence that has shown to be higher when athletes are fatigued. Therefore, the aim of the present randomized controlled trial is to evaluate the effect of fatigue, caffeine supplementation and personalized insoles on biomechanics and athletic performance in female adult soccer players.
The effect of caffeine on appetite and body weight is controversial. Mostly epidemiological studies exist that show either a negative effect (reduction of appetite and body weight) or no effect. In this trial we are going to study the results of the consumption of 5mgr/kgr body weight of caffeine on appetite, food consumption and hormones ghrelin, asprosin, leptin and pancreatic polypeptide in relation to gene polymorphisms that affect caffeine metabolism and body weight. Seventy subjects will participate in a cross sectional study consisting of two trials (with or without the consumption of caffeine) in order to study the aforementioned parameters. Differences of total calories consumption between fast metabolizers of caffeine and the rest of the participants is the primary outcome.
The mechanism of methylxanthines is thought to increase chemoreceptor responsiveness to CO2 in central nervous system. Besides, effect of methylxanthines on diaphragmatic contractility has also been found in experimental studies. A study of premature newborns has showed caffeine increase diaphragmatic activity and tidal volume. But, there is limited data about caffeine direct effect on diaphragma. Objective: The investigators aimed to show the direct effect of caffeine on diphragmatic contractility. Method: The babies under 32 weeks with respiratory support, are being enrolled in this study if caffeine treatment is decided to receive. Evaluation of muscle contraction is being made by ultrasound before and 30 minutes after caffeine loading dose. Right and left sides of diaphragm thickness are being measured by two clinicians on B mode ultrasound by anterior subcostal view. The velocity before and after caffeine administration will be calculated, dividing excursion frequency (parameter) for inspiratory time. Movement of the diaphragm at inspiratory and expiratory phases are also observed on M mode and the difference between the two phases are measured.
Nowadays,caffein is commonly used for AOP, and it reduces the intubation rate in preterm infants. However, intubation is needed in about 20%-50% of partial neonates. How to reduce the intubation rate effectively is a challenge for neonatologists.